This invention relates to an antenna assembly comprising a retractable antenna which may be applied, for example, to a portable radio and, in particular a hand portable radio telephone.
A radio intended for two-way communication generally operates with either an external fixed rod or retractable antenna, or with an internal antenna. The fixed rod type of antenna has a predetermined length. Whilst such antennas can be relatively short, they are not conductive to a compact design nor are they particularly suitable for a radio intended to be carried in a pocket or other receptacle offering restricted space. On the other hand, retractable antennas are convenient for this purpose because they can be folded away when the radio is not in use. Retractable antennas are commonly of the telescopic tube type, although retractable fixed length antennas are also known. For example, the published French applications FR-A-2,406,317 and FR-A-2,311,419 both disclose a retractable antenna in the form of a tape which can be wound up into a spiral. However, these known kinds of retractable antenna are more difficult and expensive to produce, and sufficient space must be provided within the radio casing to accommodate the antenna in its retracted form. This can contribute significantly to the overall bulk and weight and to the expense of the radio.